// let num = 100
// console.log(num);

// TS的正确的语法  // 使用脚手架工具进行编译 ts-node+文件名
let num:number = 100
console.log(num);

let str:string = 'qf_001'
console.log(str);

let un:undefined = undefined
console.log(un)

let nu:null = null
console.log(nu);

let bo1:boolean = true
let bo2:boolean = false
console.log(bo1);
console.log(bo2);

/**
 * any 什么类型的都可以使用
 * */ 
let box:any = 100
box = 'qf_001'
box = true
box = undefined
box = null
box = []
box = {}
box = ()=>{}
